Push button switch assembly



Dec. 1, 1942.

w. c. FURNAS ETAL PUSH BUTi'ON SWITCH ASSEMBLY Filed May 31, 1941 3Sheets-Sheet l i 5M2 #2? z 36 5. 1 2 I 6.

INVENTOR-S 2- w. 9. FURNAS an. 2,303,833

. PUSH mmon swn'cn ASSEMBLY Filed May 31, 1941 a Sheets-Sheet 2 [II VIll II-IAI l I I II I VII INVENTORS Dem 1942- w. c. FURNAS ETAL2,303,833

PUSH BUTTON SWITCH ASSEMBLY Filed Ma a, 1941 s Sfieets-Sheet a K I 68 L-70 1 I jgljzo C) 78 IM 53 60 l 0 I I ESE? .I'NVENTORS Patented Dec. 1,1942 PUSH BUTTON swrrcn ASSEMBLY William C. Furnas and Daniel G. Spotts,Batavia, 111.; said Spotts assignor of his entire right to said WilliamC. Furnas, doing business as Furnas Electric Company, Batavia, Ill.

Application May 31, 1941, Serial No. 396,088

7 Claims.

Our present invention relates in general to electric switch assemblages,and relates more particularly to various improvements in theconstruction and operation of push button switches and to improvementsin mechanism for effecting actuation of such switches.

Generally defined, an object of the present invention is to provide anew and useful push button switch assembly, which is extremely simple,compact and durable in construction, and which is moreover highlyefficient in operation.

Some of the more important specific objects of the invention are asfollows:

To provide an improved control switch especially adapted to cooperatewith the interlock mechanism of a magnetically actuated reversing switchor the like.

To provide an improved push button switch unit for controlling theoperation of reversible electrical devices, and which may be actuatedeither manually or mechanically.

To provide an improved control switch of the push button type, which canbe utilized in conjunction with either single or multiple-phaseelectrical systems.

To provide an improved switch assemblage having forward and reversecontrols operable either independently, or simultaneously with the aidof a common control member.

To provide an improved, forward, reverse or stop switch mechanism, whichis durable and extremely compact in structure, and wherein the variousparts are effectively insulated and protected so as to insure safeoperation.

To provide a neat and highly attractive forward and reverse controlswitch unit which is quickly and conveniently manipulable, and which isalso positive in action.

To provide improved mechanism for mechanically and automaticallyactuating a push button switch assembly having multiple controlsassociated therewith.

To provide a push button switch for high power service, the variousparts of which may be readily constructed and assembled, and which canbe conveniently installed in an electrical system.

To provide various improvements in the construction and operation ofmultiple circuit control push button switches, whereby the cost ofconstruction of such devices is reduced to a minimum, and the efiiciencyand utility thereof is enhanced to a maximum.

These and other specific objects and advantages of our presentimprovement will be apparent from the following detailed description.

A clear conception of the various improved features constituting ourpresent invention, and of the mode of constructing and of utilizing pushbutton reverse control and stop switch assemblages built in accordancewith th improvement, may be had by referring to the drawingsaccompanying and forming a part of this specification in which likereference characters designate the same or similar parts in the severalviews.

Fig. 1 is a front view of one of the improved push button switchassemblages showing the forward, reverse, and stop push buttons inelevation;

Fig. 2 is a vertical section through removable housing of the pushbutton switch assembly, showing a side elevation of the contact carrierblock and of several sets of contacts;

Fig. 3 is a central vertical section through the improved switch unit,taken along the line 33 of Fig. l and showing some of the contacts insection while others are shown in elevation;

Fig. 4 is a transverse vertical section through the switch assemblage,taken along the line 4-4 of Fig. 2, near the base of the structure;

Fig. 5 is a central horizontal section through the push button switch,taken through the stop button and along the line 5-5 of Fig. 4;

Fig. 6 is a transverse horizontal section taken along the line 66 ofFig. 4 and showing the reverse push button in normal position;

Fig. 7 is a transverse section like that of Fig. 6, but showing thereverse push button pressed down and in action;

Fig. 8 is another similar transverse section, but showing the stopbutton pressed down and effective to break all circuits.

Fig. 9 is a. diagram showing the application of the improved push buttonswitch to an electrical system having magnetically actuated forward andreverse interlock mechanisms associated therewith;

Fig. 10 is a transverse horizontal section through an improved cammechanism for efiecting mechanical actuation of the improved push buttonswitch unit, the section being taken along the line Ill-40 of Fig. 11;

Fig. 11 is a side elevation of the improved push button switch andmechanical actuating mechanism therefor;

Fig. 12 is a vertical transverse section through the improved mechanicalactuating mechanism, taken along the line [2-42 of Fig. 11; and

Fig. 13 is a diagram similar to that of Fig. 9 but showing themechanical actuating mechanism applied to the switch mechanism.

While the invention has been shown and described in conjunction with aforward, reverse and stop push button switch disposed in a particularposition and especially cooperable with magnetically actuated interlockmechanism, it is not desired to thereby unnecessarily restrict the scopeor utility of the improved features, and the switch can obviously bedisposed otherwise than vertical as shown.

Referring to Figs. 1 to 9 inclusive of the drawings, the improved pushbutton switch unit shown therein, is especially adapted for cooperationwith the magnetically actuated interlock mechanism of a reversingelectrical system, and comprises in general a contact support or carrierblock l5 formed of insulating material and being rigidly secured to aU-shaped metal supporting bracket or frame ll; sets of upper and lowerfixed forward and reverse normally connected or closed contacts l8, l9respectively, firmly secured to the rear portion of the carrier blockl6; sets of upper and lower fixed forward and reverse normallydisconnected or open contacts 23, 2i spaced rearwardly from the contacts|8, |9 respectively and being suspended from the block it; upper andlower forward and reverse movable contacts 22, 23 respectively, carriedby upper and lower angular slide bars 24, 25 coacting with parallelslots 26 in the block l6, and being movable between the fixed closed andopen contacts by means of forward and reverse buttons 21, 23respectively; compression springs ZQ interposed between the oil-set ends30 of the bars 24, 25 and the block l6, for constantly urging themovable contacts 22, 23 toward t. e corresponding fixed closed contacts!8, |9; an elongated plate 3| of insulation slidably confined within arecess 32 in the front of the block and being cooperable with shoulders33 on the opposite sides of the forward and reverse buttons 21, 28 tosimultaneously push these buttons rearwardly; a central stop button 34rigidly attached to the medial portion of the plate 3| and having acentral guide and retaining car 35 cooperable with parallel slots 36formed in the block I G; and a housing or enclosing cover 3'! detachablysecured to the frame I? by a screw 38 and coacting with the block is andthe frame to conceal the several contacts.

As previously indicated, the contact carrier block i5 is preferablyformed of insulating material, and the upper and lower ends of thisblock are provided with spaced lugs 39 coacting with punched holes inthe U-shaped frame ll so as to rigidly interconnect these elements, seeFigs. 2, 3 and 4. The rear portion of the block I6 is provided withintegral flanges 40, and a U-shaped insulation shield 4| coacts with theframe I! and with the flanges 43 to provide an enclosed zone withinwhich the several contacts are normally confined. The sets of parallelslots 26, 33 which are formed in the contact carrier block l3 arepreferably separated by circular holes 42 as shown in Figs. 3 and 4, inorder to reduce the friction, and the foremost portion of the block I3adjacent to the recess 32 forms a bead 43 projecting outwardly beyondthe cover 37 and functioning to properly position the same.

The adjacent fixed normally closed and open contacts |8, 2| areinterconnected by means of a permanent conductor plate 44, and theopposite adjacent fixed normally closed and open contacts i9, 23 arelikewise interconnected by means of a permanent conductor plate 45. Theopen contacts 20, 2| are normally connected to interlock mechanisms orcontacts 46, 41 which are respectively operable by means for forward andreverse electromagnet assemblages 48, 49 as shown diagrammatically inFig. 9; and the main power line 50 may be connected to the outercontacts I8, 23 while the magnet assemblages 48, 49 are connected inseries with the outer contacts i3, 2!, The conductors may be introducedinto the enclosure afforded by the frame and cover 31 through an opening5|, and may be connected to the proper contacts by means of terminalscrews 52, see Figs. 2, 3 and 4.

The supporting frame l7, contacts I3, I53, 23, 2|, 22, 23, bars 24, 25,35, and cover 31 may all be formed of sheet metal with the aid ofpunches and dies; and the push buttons 21, 23, 34 may be formed ofmoulded insulation the same as the block I6, while the plate 3| mayeither be formed of moulded insulation or of plate insulation stock. Thesliding guide bars 24, 25 which carry the movable contacts 22, 23, havetheir outer ends 38 bent laterally and secured to the forward andreverse buttons 21, 28 respectively by means of attaching screws 53within recesses in these buttons, and the springs 29 are retained withinconfining sockets 54 in the block l6 by these same screws 53. Theopposite ends of these contact carrier bars 24, 25 are bifurcated asshown in Figs. 4 and 6, and are provided with notches 55 which aresprung into central slots 55 in the contacts 22, 23 to flexibly suspendthe latter and to permit slight lateral rocking thereof. The fixedcontacts is, I9, 23, 2| are all rather rigidly suspended from the blockIE, but the movable contacts 22, 23 can rock slightly, so that perfectelectrical engagement will be assured between the various contactsduring normal use of the switch. The central guide bar 35 which isfreely slidable in the slots 36, has its forward end 5'! bifurcated andsprung into the stop button 34 and plate 3|, while its opposite end isprovided with laterally projecting retainer lugs 58 slidable in grooves59, as shown in Fig. 5. All of the elements of the switch assembly maybe conveniently constructed and assembled, and are normally concealedand protected by the housing cover 31 which may however be readilyremoved for access and inspection purposes.

During normal use of the improved manually operable reversing switchassemblage shown in Figs. 1 to 9 inclusive, and assuming the switch tohave been properly introduced in an electrical circuit havingmagnetically actuated interlocks as shown in Fig. 9, the buttons 21, 23,34 and the plate 3| will normally be positioned as shown in Figs. 3 and9 with the movable contacts 22, 23 engaging the fixed closed contactsl8, IS. The springs 29 will normally maintain the elements in suchposition, and these springs 23 while coacting directly with the buttons21, 23, also coact indirectly with the plate 3| and stop button 34through the flanges 33 formed on the opposite sides of the buttons 21,28.

If it becomes desirable to operate the electrical mechanism for reverse,the reverse push button 28 may be pressed and thereby moved from theposition shown in Fig. 6 to that shown in Fig. 7. The movable contact 23will then engage the normally open contacts 2| and will thereby energizethe electromagnet 43, and will cause the interlock contacts 41 to closeand become effective. The reversible electrical device which may be anelectric motor or any other suitable apparatus,

will then operate in reverse and will continue to so operate as long asthe interlock contacts 41 are held in active or closed position by theelectromagnet 49, even if the push button 28 is released.

When the push button 28 is released, it will return to normal positionin engagement with the plate 3l, and if the stop button 34 issubsequently pressed, the movable contacts will be shifted to theposition shown in Fig. 8 and the electrical circuit through the contacts41 and electromagnet 49 will be broken since both movable contacts 22,23 will then be carried out of engagement with all of the fixedcontacts. Upon release of the stop button 34, the mechanism will againassume the position shown in Figs. 3 and 9 and will be ready for eithersubsequent reverse operation or for forward operation.

If it becomes desirable to produce forward operation of the motor orother electrical device, it is only necessary to press the forward pushbutton '21 whereupon the movable contact 22 will be carried intoengagement with the fixed normally open contacts and th electromagnet 48will be energized thereby causing the interlock contacts 45 to close.Upon release of the push button 21, this button will return to normalposition by the spring 29, but the interlock contacts 46 and theelectromagnet 48 will remain active until the stop'push button 34 isagain manipulated. When the button 34 is pressed, both mov able contacts22, 23 will again be carried into mid-position as shown in Fig. 8,thereby opening all circuits and de-energizing the electromagnet 48.Upon release of the button 34, the springs 29 will again return allbuttons to neutral position as shown in Figs. 3 and 9 and the switchmechanism is again ready for subsequent either forward or reverseoperation. If it becomes desirable to produce reverse operation of themot-or or other device, While the same is operating in forwarddirection, it is only necessary to press the reverse push button 28which then moves from the position shown in Fig. 6 to that of Fig. '7.This actuation causes the movable contact 23 to first disengage thefixed contacts 19 which in turn de-energizes the forward mechanism, andas the movable contact 23 engages the other fixed contacts 2| thereverse mechanism will become effective. The conversion from forward toreverse operation may therefore be effected directly ing the forwardbutton 21 when the reverse mechanism is in action.

While the manual operation just described may be satisfactory for mostuses of the improved push button switch unit, it sometimes becomesdesirable to have the improved switch mechanism automatically operable,and such operation may also be effected by utilizing the improved switchactuating assemblage shown in Figs. 10 to 13 inclusive. The mechanicallyactuated switch unit embodies the same contact supporting block IE butwith the upper retaining lugs 39 removed, and also embodies the samecontact assemblage including the fixed normally closed and open contactsI8, I9, 20, 2|, and the movable contacts 22, 23 carried by actuatingbars 24, slidable in the block I6. However, the supporting frame I! hasbeen replaced by an approximately rectangular frame -60 provided withremovable covers SI, 62 secured to its opposite sides by means of Cirscrews 63. The contact carrier block is secured within the frame 60 bymeans of cleats 64 and other screws 6'5, and the push buttons 21, 28, 34as well as the plate 3| have been omitted and replaced by a double cam66 fixedly mounted upon an oscillatory shaft 6'! supported in bearings68, 69 secured to the frame 60. The upper swinging end of the lever cam66 coacts with the upwardly offset end 30 of the upper bar 24 whichcarries the movable contacts 22, while the lower swinging end of thiscam '66 coacts with the downwardly offset end of the lower bar 25 whichcarries the other movable contact 23, and the compression springs 29constantly maintain the offset bar ends in engagement with therespective ends of the cam lever. The oscillatory cam supporting shaft61 projects through the covers '6 I, 62 and one end thereof may beprovided with a positioning lever 10 shown in dot-and-dash lines in Fig.10, and in solid lines in Fig. 13, and this lever 10 may be responsiveto various conditions of operation of the reversible electrical motor orother device the operation of which is being controlled. The lever 10may also be manually operable, and in order to frictionally retain theswitch contacts in either neutral or forward or reverse stop position,the shaft 61 is also provide-d with a rigidly attached bracket or arm Hhaving spaced flanges l2, 13 in which a latch bar 14 is slidablyconfined. The outer end of the bar 74 carries a roller 15 which isfrictionally co-operable with forward and reverse spaced holding notchesH5, 11 respectively, and with a central stop notch 18 formed in a fixedpositioning plate 19 secured to the frame 60. The bar 14 and roller 15are constantly urged toward the plate 19 by a compression spring '80embracing the inner bar end and reacting against the flange l2, and theplate 19 also has cam end surfaces 8 I, 82 located outwardly beyond theholding notches l6, 11 respectively, which permit the shaft 61 to beforcibly swung beyond the hold notches 16, H in order to energize theinterlock actuating magnets 48, 49, but which also return the roller T5to hold position without interrupting the interlock circuit, when theactuating force is released. The plate 19 may be adjustably secured tothe frame 60 by means of screws 83, and the medial square portion of theshaft 61 on opposite sides of the lever cam 66 is preferably embraced bysquare insulating sleeves 84 clamped in position by a nut 85 threaded onthe shaft and coacting with a lock washer 86.

During normal use of the improved automatically operable reversingswitch assemblage shown in Figs. 10 to 13 inclusive, and assuming theswitch to have been properly introduced in an electrical circuit havingmechanically actuated interlocks as shown in Fig. 13, the actuatinglever 10 and the lever cam 66 will normally be in stop position as shownin Fig. 13 with the movable contacts 22, 23 out of engagement with allof the fixed contacts so that the circuit through both sets of contactswill be interrupted. While the retaining notches 16, ll, 18 and the camsurfaces BI, 82 have not actually been shown in the diagram of Fig. 13,the corresponding positions of the lever 10 are shown and arecorrespondingly numbered.

If it becomes desirable to operate the electrical system in reverse, thelever 10 and the lever cam 66 may be swung in a counter-clockwisedirection from the position shown in Fig. 13, thereby first causing themovable contact 22 to engage the fixed contacts 18, and subsequentlycausing the movable contact 23 to engage the fixed contacts 2|. Thissequence of actions is produced by the formation of the notches and camsurfaces on the plate 19, and when the actuating force on the lever if!is released, the cam 82 will automatically cause the roller '15 toengage the reverse holding notch 1?, thereby maintaining the movablecontact 22 closed and in engagement with the fixed contacts l3, whilepermitting the spring 29 to withdraw the other movable contact 23 fromthe fixed contacts 2i. Z'he electro-magnet d9 will remain energized sothat the reverse interlock contacts 4? will remain closed as long as theline contacts 58 are engaged by the movable contact 22; and in order tobreak the reverse interlock circuit, it is necessary to return the lever13 to neutral position with the roller 75 engaging the notch '18 asshown in Fig. 13, whereupon all circuits will be interrupted.

If it becomes desirable to produce forward operation of the reversibleelectrical device, the lever 13 should be swung in a clockwise directionfrom the position shown in Fig. 13, whereupon the movable contact 23will first engage the fixed contacts 49 to close the line circuit, andthe movable contact 22 will subsequently engage the fixed contacts 25 tocomplete the magnetic circuit and to energize the forward magnet 43,thereby causing the interlock contacts 6 to close. Upon release of thelever Til, the roller 75 will be forced by the cam surface 8| to engagethe notch it? and while the movable contact 22 will be withdrawn fromthe fixed contacts 23, the other movable contact 23 will remain closedand in engagement with the fixed contacts i9, thereby maintaining theinterlock contacts &8 closed until all electrical circuits aresubsequently interrupted. Such interruption may be effected by returningthe lever E0 to neutral position with the roller '15 in engagement withthe notch 18, and from this neutral position the mechanism may bequickly thrown into either forward or reverse position. The lever 79 mayalso be swung quickly from one extreme position to the other to therebyconvert the system directly from forward to reverse operation, or viceversa, without arresting the lever in stop position.

From the foregoing detailed description it will be apparent that thepresent invention provides an improved push button switch assemblagewhich is extremely simple, compact and durable in construction, andwhich is moreover rapid in action and efiicient in operation. Theimproved push button assemblage is especially adapted for use inconjunction with an electrical system having forward and reverseinterlocks associated therewith, and can be either manually orautomatically actuated to effectively produce the desired results. Theimproved switch mechanism may obviously be utilized either inconjunction with single or poly-phase electrical systems, and theforward and reverse controls while being interchangeably operable toeffect forward and reverse operation, may be simultaneously returned toneutral with the aid of a common control lever or push button. Thevarious elements of the improved switch assembly are effectivelyinsulated and protected in order to insure safe operation, and theimproved switch mechanism is especially adapted for use in relativelyhigh power electrical systems wherein absolute assurance against shortcircuiting is necessary. The various elements of both the swi ch andmechanical control may obviously be manufactured and assembled atmoderate cost, and the units may also be conveniently applied toelectrical systems in the manner shown in the several diagrams. Theimproved switch assemblage has proven highly successful in actual use,and presents an extremely neat and attractive appearance as will beapparent from the drawings.

It should be understood that it is not desired to limit this inventionto the exact details of construction or to the precise mode ofoperation, herein shown and described, for various modifications withinthe scope of the claims may occur to persons skilled in the art.

We claim:

1. A switch comprising, a unitary support having recesses in itsopposite sides connected by three parallel guide-ways, laterally spacedsets of contacts fixedly mounted in one of said recesses, othersimilarly spaced sets of fixed contacts mounted in the same recess andbeing separated from said first mentioned contacts by spaces,independent sets of movable contacts carried within said spaces by barsslidably engaging the two outer guide-ways and penetrating said support,said bars having oppositely outwardly oil-set portions remote from saidcontacts and extending away from each other, spring means coacting withsaid support and with said off-set portions for constantly urging saidmovable contacts in one direction, independently operable push buttonsco-operable directly with said airset portions within the other of saidrecesses for moving said movable contacts in the opposite direction, andanother push button located between said independently operable buttonsand being slidably mounted within said other recess and cooperable withsaid off-set portions to simultaneously move said movable contacts.

2. A switch comprising, a unitary support having three laterallyseparated parallel elongated guide-ways connecting its opposite sides,laterally spaced fixed contacts mounted on one side of said support,other similarly spaced fixed contacts mounted on the same side of saidsupport and being separated from said first mentioned contacts byspaces, two independent movable contacts carried within said spaces bylaterally separated parallel bars slidably engaging the two outerguide-ways and penetrating said support, said bars having oppositelyoutwardly off-set portions remote from said contacts and extending overthe opposite side of said support, springs interposed between saidsupport and said off-set portions, independently operable push-buttonscoacting with said off-set portions for compressing said springs, and acommon actuator for said push buttons coacting with the intermediateguide-way of said support and being simultaneously cooperable with bothof said movable contacts.

3. A switch comprising, a unitary support havthree parallel guide-waysconnecting recesses in its opposite sides, laterally spaced fixedcontacts mounted on one side of said support in one of said recesses,other similarly spaced fixed contacts mounted in the same recess of saidsupport and being separated from said first mentioned contacts byspaces, two independent movable contacts carried within said spaces byparallel bars slidably engaging the two outer guideways and penetratingsaid support, said bars having oppositely outwardly off-set portionsremote from said contacts and extending over the opposite side of saidsupport within the other of said recesses, springs interposed betweensaid support and said off-set portions, push buttons coacting with saidoft-set portions within said other recess for independently moving saidbars in one direction, and another push button coacting with theintermediate guide-way between said oiT-set portions and being slidablein said other recess to simultaneously move said bars.

4. A switch comprising, a unitary support having three parallelguide-ways connecting its opposite sides, laterally spaced fixedcontacts mounted on one side of said support, other similarly spacedfixed contacts mounted on the same side of said support and beingseparated from said first mentioned contacts by spaces, two independentmovable contacts carried within said spaces by parallel bars slidablyengaging the two outer guide-ways and penetrating said support, saidbars having oppositely outwardly off-set portions remote from saidcontacts and extending over the opposite side of said support, springsinterposed between said support and said offset portions, laterally ofsaid bars, independently operable push buttons coacting with saidoiT-set portions and having peripheral projections, and a plate coactingwith the intermediate guide-way and slidable upon said support and beingengageable with said button projections to simultaneously actuate thebuttons.

5. A switch comprising, a unitary support having three laterallyseparated guide-ways connecting its opposite sides, laterally spacedfixed contacts mounted on one side of said support, other similarlyspaced fixed contacts mounted on the same side of said support and beingseparated irom said first mentioned contacts by spaces, two independentmovable contacts carried within said spaces by laterally separated barsslidably engaging the two outer guide-ways and penetrating said support,said bars having ppositely oil-set portions remote from said contactsand extending 'over the opposite side of said support, springsinterposed between said support and said ofi-set portions, independentlyoperable push buttons coacting with said ofi-set portions and havingperipheral projections, a plate coacting with the intermediate guide-wayand slidable upon said support and being engageable with said buttonprojections, and another push button coacting with said plate midwaybetween said oft-set bar portions for simultaneously actuating saidindependently operable buttons.

6. A switch comprising, a unitary support having three parallelguide-ways connecting its oppesite sides, laterally spaced fixedcontacts mounted on one side of said support, independent movablecontacts carried by parallel bars slidably engaging the two outerguide-ways and penetrating said support, said movable contacts beingcooperable with said fixed contacts and said bars having oppositelyoff-set portions re mote from said contacts and extending laterallythereof over the opposite side of said support, springs interposedbetween said support and said oft-set bar portions, an independentlyoperable push button coacting directly with each of said oil-setportions in opposition to the adjacent spring, and a common actuatingplate for said push buttons coacting with the intermediate guide-way andbeing simultaneously engageable with both of said buttons.

7. A switch comprising, a unitary support having three laterallyseparated guide-ways connecting recesses in its opposite sides,laterally spaced fixed contacts mounted in one of said recesses,independent movable contacts coacting with said fixed contacts and beingcarried by laterally separated bars slidably engaging the two outerguide-ways and penetrating said sup-port, said bars having oppositelyoff-set portions in the other of said recesses extending laterallythereof, springs interposed between said support and said off-setportions, a push button coacting directiy with each of said off-setportions in opposition to the adjacent spring and eccentrically of theadjacent bar, and a common actuating plate for said push buttonsslidable within said other recess and coacting with the intermediateguide-way, said plate being movable in a direction parallel to thedirection of extent of said guide-ways to simultaneously actuate both ofsaid push buttons.

WILLIAM C. FURNAS. DANIEL G. SPOTTS.

